4种豆科绿肥养分含量及其对土壤培肥效应分析

Nutrient content of four different Leguminous green manure and its effect on soil fertility improvement potential

[目的]本文旨在明确在不施用化肥的情况下豆科绿肥作物体内养分含量变化及其翻压还田后对土壤肥力的影响。[方法]于2021年10月至2022年5月,通过田间试验研究紫云英、毛叶苕子、蚕豆、箭筈豌豆4种豆科绿肥的生长发育和氮、磷、钾养分含量,并分析绿肥翻压还田后对土壤养分含量的影响。[结果]不同绿肥在苗期与生育后期全氮、全磷和全钾养分含量变化趋势相似,生育后期的养分含量显著高于苗期,干物质量达1 800 kg·hm^(-2)以上,适宜翻压。在生育后期,毛叶苕子的全氮含量(3.34%)和全磷含量(0.29%)显著高于其他3种绿肥,紫云英的全钾含量(3.58%)最高,且差异显著。紫云英和毛叶苕子的氮、磷、钾养分累积量相对较高,蚕豆和箭筈豌豆相对较低。4种豆科绿肥还田,土壤pH值没有显著影响,土壤有机碳、全氮、有效磷和速效钾含量均增加,提高了2.71%~29.50%。其中紫云英还田可以显著提高土壤肥力,土壤有机碳、全氮、有效磷和速效钾含量与休耕相比分别增加了4.04%、3.40%、29.50%和8.22%。[结论]在不额外施用化肥时,种植紫云英有利于土壤肥力提升。

[Objectives]This paper aimed to clarify the change of nutrient content in Leguminous green manure crops and its impact on soil fertility with none extra chemical fertilizer.[Methods]The experiments were conducted to study the growth and development of four Leguminous green manure crops from October 2021 to May 2022 in field.They were Chinese milk vetch(Astragalus sinicus L.),hairy vetch(Vicia villosa Roth.),broad bean(Vicia faba L.)and common vetch(Vicia sativa L.),respectively.The nutrient contents of nitrogen(N),phosphorus(P)and potassium(K)in green manure crops as well as the soil nutrient content were measured.[Results]The changes in N,P,K nutrient content of different Leguminous green manure crops during the seedling stage and later growth stage were similar.Four Leguminous green manure crops had significantly higher nutrient content at the later growth stage than at the seedling stage,with biomass of dry weight of over 1800 kg·hm^(-2),making them suitable for flipping.In later growth period,the total N content(3.34%)and total P content(0.29%)of hairy vetch were significantly higher than the others,while the total K content of Chinese milk vetch(3.58%)was the highest and the difference displayed a significant level.The accumulation of N,P and K nutrients in Chinese milk vetch and hairy vetch was relatively high,while that in broad bean and common vetch was relatively low.The pH value of soil did not change with green manure application.After growing Leguminous green manure,the organic carbon content in soil as well as total N,available P and available K contents increased,with a range of 2.71%-29.50%.Among them,the application of Chinese milk vetch to the field could significantly improve soil fertility,and the organic carbon,total N,available P and available K contents increased by 4.04%,3.40%,29.50%and 8.22%compared to fallow cultivation,respectively.[Conclusions]Under the condition of disappeared application of chemical fertilizer,Chinese milk vetch was conducive to improving soil fertility.